This invention relates to keyboard means and more particularly to an arrangement of discrete signal operating elements intended for manual operation.
Various attempts have been made to arrange keyboards in a convenient manner. Most of these arrangements comprise the movably affixing of push-buttons to walls of a housing, presenting a substantially planar pattern. Within this context of planar arrangement the buttons have been variously arranged from the now all too familiar desk calculators and push-button telephones to the older and well-established calculators, typewriter keyboards and the like.
From time to time, some effort has been made to alter this arrangement with only limited success. Thus, Hofgaard (U.S. Pat. No. 2,261,115) discloses a plurality of planar disposed keys wherein the keys are in close proximity to one another and in stepped relationship thereto. Thus, in operation, one or more keys are pressed at the same time. While this arrangement clearly makes for a more compact keyboard, it presents the same operational difficulties as will be discussed hereinafter in connection with the flat or planar keyboard arrangement currently in use.
Still another suggestion is proposed by Taylor (U.S. Pat. No. 2,628,030). Taylor discloses a substantially planar key arrangement with several of the keys, such as the add or subtract button, having bevelled edges and at least three of the numeral keys having a concave top surface so that the operator may simply and easily locate his hands on the keyboard. However, like Hofgaard and the others herein, Taylor presents the similar flat keyboard arrangement.
Heindorff (U.S. Pat. No. 2,727,689) presents buttons lying in concave configuration. The difficulty with this arrangement is that the fingers must still move from one key position to another.
Frenkel (U.S. Pat. No. 3,096,019) discloses five switches each having an intermediate position. The operator merely pivots the switch from one position or another to actuate numbers zero through nine. While this particular system is compact, it is in no way adaptable to presently existing push-button arrangements. Further, the pivot arrangement requires an education of the user as to which numbers are in which location. Thus, a calculator constructed in connection with the teachings of Frenkel would require the user to be re-educated in a manner different from that commonly used.
Clearly, in order to improve the efficiency of one using a calculator-type push-button array of buttons would be to arrange those buttons such that the user would be able to reduce movement to a minimal direction. As presently constituted, the established buttons require a plurality of movements first in one direction followed by a downward movement upon the button. With this requirement there is an obvious loss of efficiency and a consequent loss of time.